Windows CE 5.0, How to restore registry setting

Dear all

Device: Psion Teklogix Workabout Pro3

Operating system: Win ce 5.0

<big>Action performed:</big> In registry (HKLM / Init), entry Launch 80: explorer.exe has been replaced by Launch 80: myApp.exe.

<big>Problem occurred:</big> After restart of device, device has been stuck at white screen.

Please help that how registry entry can be modified to old entry.

Actually, I was trying to run my application on startup and without Desktop display. My application uses remote connection, camera and serial port too.

Thanks in advance.